Acoustical surfaces



Sept. 22, 1964 F. c. KELLER ETAL 3,149,693

ACOUSTICAL SURFACES Filed Aug. l, 1960 Eig@ `INVENTORS E C. KELLER 6Ll?. HARP/s United States Patent O 3,149,693 ACUSTCAL SURFACllS Fred C.Keller, Thornville, and Ronald R. Harris, Newark, (Ehio, asslgnors toOwens-Corning Fiberglas Corporation, a corporation of Delaware FiledAug. 1, 1960, Ser. No. 46,564 3 Claims. (Cl. 1811-4-53) This inventionrelates to improved acoustical surface panels for ceilings and walls andto a method of applying such panels.

The use of acoustical ceiling tiles is becoming more and morewidespread, particularly in commercial buildings and also in less formalrooms of residences, such as recreation rooms. Ceiling tiles areproduced in units usually measuring one foot square, although largertiles are not uncommon, and have beveled edges so that the individualtiles are readily discernible after being applied to a ceiling or wall.Because of the overall appearance produced by the installed acousticaltiles, they are seldom used in more formal rooms of houses, such asliving rooms, dining rooms, and bedrooms. Larger ceiling boards, whichare similar to acoustical tiles but are of rectangular shape, usuallymeasuring 2 x 4 or larger, are also used, frequently supported below aceiling by metal T-bars which are exposed below the ceiling boards,thereby giving a broken appearance to the overall ceiling similar tothat obtained with acoustical tiles. lence, acoustical ceiling boardsare generally limited to the same applications for which ceiling tilesare used.

The present invention provides an acoustical surface panel and a methodof applying such a panel to a basic wall or ceiling structure. The newpanels, when in place, provide a smooth appearance with no joints orseams whatsoever being visible. Hence, the surface product with the newpanels looks similar to a textured plastered wall and can be usedwhenever plastered walls are deemed appropriate which includespractically any room in a commercial building or house, including themore formal rooms such as living rooms, dining, rooms, and bedrooms.

Basically, the new panels consist of fibrous, sound-abn sorbing boardspreferably made of glass fibers because of their very high degree ofsound absorption. The iibrous boards are stapled or otherwise affixed inabutting relationship to structural members constituting part of thewall or ceiling to which the acoustical panels are to be applied. Sheetsof bonded mats of glass bers are then adhered to the exposed faces ofthe ilbrous boards with the edges of the sheets in abutting relationshipand staggered with respect to the abutting joints of the brous boards sothat old joints are almost imperceptible. With the sheets of bonded matin place, an acoustical paint is then applied to the exposed surfaces ofthe sheets to completely hide all joints and to give the effect of acontinuous slightly textured surface. Acoustical panels according to theinvention are as effective in .absorbing sound as are conventionalacoustical tiles and will not crack as does plaster. Hence, the panelscombine most of the advantages of both acoustical tiles and plasteredwalls without incurring the disadvantages thereof.

lt is, therefore, a principal object of the invention to provide anacoustical panel capable of absorbing a high percentage of sound yetstill having a smooth, unbroken appearance, rendering a wall or ceilingmade of such panels suitable for use in many environments.

Another object of the invention is to provide a method of applyingacoustical panels to a basic wall or ceiling structure, which methodproduces an unbroken surface, free of any visible joints.

ICC

A further object of the invention is to provide a soundabsorbing wall orceiling structure which has an appearance somewhat similar to plasterbut does not have a tendency to crack or spall.

Other objects and advantages of the invention will be apparent from thefollowing detailed description of preferred embodiments thereof,reference being made to the accompanying drawing, in which:

FIG. l is a sectional view in perspective of a ceiling or Wall structureembodying the principles of the invention;

FIG. 2 is a fragmentary, sectional view on an enlarged scale of aportion of an acoustical panel which is a part of the structure of FIG.1;

FG. 3 is a fragmentary, sectional view on an enlarged scale of aslightly modified panel;

ilGS. 4 8 are fragmentary, ectional edge views of elements of theacoustical panels of FIG. l and showing the steps employed in applyingsuch panels on a wall or ceiling structure;

FIG. 9 is an enlarged view of a portion of a sheet of bonded liber matemployed in the acoustical panel; and

FIG. l0 is a greatly enlarged view of a portion of the mat shown in FIG.9 with a coating of paint on part of the Inat.

Referring to FIG. 1, a wall or ceiling structure indicated generally at10 includes structural members 12 and acoustical panels according to theinvention which are indicated generally at 14. While the panels 14 makean excellent acoustical ceiling, they are equally effective for walls.ln 'the latter instance, the panels are preferably used only above aheight of three or four feet, with more shock-resistant panels usedtherebelow, because the panels le are subjected to damage when strucktoo hard, although they are more shock resistant than most conventionalacoustical tiles. The structural members 12 are shown as wooden studsbut can be numerous other structures such as concrete blocks on steelbeams, for example, and where the acoustical panels 14 are applied onold walls, the structural members 12 might constitute a combination ofstudding, lath, and plaster, plaster board, or plywood, by way ofillustration. In the case of concrete blocks, or similar materials intowhich nails or staples cannot readily be driven, furring strips can beemployed, l x 3 boards being suitable for this purpose.

The panels 14 basically include fibrous boards 16, preferably of glassfibers, which are backed with layers 1S of heavy paper adhered thereto.Strips of heavy paper can also be used behind the joints of the boards16. Sheets Ztl of bonded fiber mat are adhered to the eX- posed faces ofthe fibrous boards 16 with abutting joints indicated at 22. The joints22 are staggered relative to joints 24 between adjacent ones of theboards 16. Finally, a coat 26 of acoustical paint covers the exposedside of the bonded mat sheets Ztl. The board joints 24 are hidden by thesheets 20 and the abutting joints 22 of the sheets 20 are barely visiblebefore the paint coat 26 is applied and cannot be seen at allthereafter.

Referring now in more detail to FlG. 2, which shows the nature of thespecific elements of the panels 14, the fibrous boards 16 are preferablymade in 2 x 4' rectanguiar sections, each having a thickness ofapproximately Si, although larger and smaller as well as thicker orthinner panels can be used. The boards preferably consist of intertwinedglass fibers which are densified and bonded together with a phenolicresin, resulting in an apparent density of the fibers and binder ofapproximately 9 pounds per cubic foot. Glass liber boards of this naturewith apparent densities between approximately seven pounds per cubicfoot and approximately twelve pounds per cubic foot have been found tobe suitable for the panels 14. Fibrous boards with densities below aboutseven pounds per cubic foot tend to lack suicient stiffness while boardswith densities above approximately twelve pounds per cubic foot are moreexpensive and heavier, due to the additional materials employed therein,without adding any benefits to the panels 14.

l The layer 18 of paper backing on each of the boards 16 is used toreduce the amount of air liow therethrough. Such air liow tends to occurquite readily when slight pressure variations occur in a room in whichthe panels 14 are located because the boards 16 are quite porous, andwhen the air flows through the panels 14 from the exposed side, itdeposits air-borne dirt thereon and causes the surfaces to darken orsoil over a period of time. While the panels 14 can be repainted withoutany great loss in sound absorption, the period of thne before soilingbecomes apparent can be lengthened by using the paper layer 1S to reducesuch air iiow. In a specilic ernbodiment of the panel 14, a 40 poundnatural kraft paper is adhered to the rear side of the boards 1t withasphalt applied in an amount of four ounces per square foot.

The bonded glass liber mat 20 basically is made of long, glass filaments20a (FlGS. 9 and 10) having diameters in the order of 0.00060 inch whichare arranged in overlapping swirl patterns. The overlapping filamentsare dipped in a phenolic binder consisting essentially of 42 pounds of a50% solids deionized resole, 35 pounds of an 88% solids bone glue, andenough water to make 80 gallons of the binder. The binder in the bondedmat preferably ranges from to 25% by weight, and, most desirably, fromto 21% by weight. The mat 20 has a thickness of approximately 0.015 andweighs approximately 0.012 pound per square foot, depending principallyupon the amount of binder employed. It is packaged in rolls which arethree feet wide and are of varying lengths, up to 5000 feet. T he mat2li, as described above, is stiffer than most bonded mats known in theart in order to facilitate its application to the xposed surfaces of thefibrous boards 16 without excessive wrinkling. ness can be achieved byusing more binder Zlib (FIG. 10) than is normally used, by using aharder binder, or by using a thicker layer of continuous glassfilaments, The binder in the mat 2.0 adheres the overlapping rberstogether `at their points of intersection but does not cornpletely lillinterstices between the bers so that many gaps are present through themat.

The mat is adhered to the exposed faces of the fibrous boards 16 with anadhesive Z1( FIG. 2) containing a binder which dries rather quickly, iswater resistant, and is somewhat elastic. The adhesive also must notdeleteriously affect the binder in the board 16 whether it be phenolic,urea, melamine, mixtures thereof, or other materials. Solutions ofpolyvinyl acetate in toluene have been found suitable for use in thisadhesive, as well as rubber-type cements, for example.

The acoustical paint in the coat 26 can be a Water based latex type,several of which are known in the art. The paint preferably coalesces onthe surface of the mat 20 in small individual globules 26a (FlG. 10)which cover only some of the gaps in the mat 20 and leave the surface ofthe mat quite porous. The globules of paint give a slightly texturedappearance to the surface to the panels In some instances, it ispreferred to fasten plaster board or the like to the structural members12 before applying the fibrous boards 16. Accordingly, a plaster board23 of FIG. 3 can be nailed or otherwise fastened by fasteners 29 to themembers 12 with the fibrous boards 16 then applied to the plaster board28 with acoustical mastic 28a or the like. In this instance, the layer18 of backing paper is eliminated because its purpose is served by theplaster board.

The acoustical panels 14- are applied to the structural components of awall or ceiling according to the following technique:

The stiff- The fibrous boards 16 are first fastened in abuttingrelationship to theA structural members 12 of FIG. 1 or other structuralportions of the ceiling or wall, staples 30 (FIG. 4) being preferredwhen the structural portions are of an appropriate nature, The staples30 have good holding power and can be applied quickly with numeroustypes of staple guns now known in the art. The staples are applied sothat their transverse portions are hush with the exposed surfaces of theboards 15.

Adhesive 31 is tuen applied to the boards 16 over an area designated 32(FIG. 5) and one of the sheets 20 is adhered thereto with portions 34-at all four edges thereof extending beyond the adhesive area 32. Withone of the sheets 20 in place, a second area 32 (FIG. 6) of adhesive 31is applied on the fibrous boards 16 and a second of the sheets 2t? isplaced thereon with a second of the portions 3d overlapping the portion34 of the lirst of the sheets 20. Gther edge portions of the sheets Ztlat the upper or lower edges thereof also overlap any adjacent sheets ina similar manner. Parts of the two overlapped portions 34 are thensevered, preferably by running a sharp edge through the two portions 34along a single cutting line represented in FIG. 6 by a line 36.Remaining parts 33 of the overlapped portions 34 are then pulled back,away from the board 16, as shown in FlG. 7, and the severed parts of theportions 34 are discarded. The remaining parts 3S of the overlappingportions 3d can then be held back by means of pins 40 or the like whichare inserted through the sheets 2li and into the board 16. An exposedportion t2 of the hoard 16 between the sheets 20 is then covered byadhesive d3, as from a spray 44 of a spray apparatus 46. The pins 40 areremoved subsequently and the remaining parts 35 are adhered to theadhesive on the portion 42 of the board 16 in substantially perfectabutting relationship. A smooth surface is thereby effected with theseams or joints of the abutting sheets 20 barely visible.

The coating 26 of acoustical paint is then sprayed on, or otherwiseapplied to, the exposed surfaces of the sheets 20 of bonded mat, asshown in FIG. 8, to complete the acoustical surface. The acousticalpaint globules 26a form a discontinuous layer on the sheets 2), coveringsome of the gaps therein, but leaving many of the minute gaps exposed,whereby the entire acoustical surface is discontinuous, with openingsextending through both the paint coat 26 and the sheets 20 to thefibrous, soundabsorbing boards 16 to enable sound to enter the boards16. The individual gaps and the paint globules surrounding them are notreadily discernible, per se, but give an overall t xtured effect to thewall. The surface of the wall is entirely free of any visible seams orjoints and has the appearance of textured plaster. Because the fibrousboards 16 and the mat Ztl are somewhat elastic, the acoustical surfacecannot crack as does plaster due to shrinkage, shift in the structuralportion of the wall, or the like.

Various modifications of the above described embodiment of the inventionwill be apparent to those skilled in the art, and it is to be understoodthat such modiiications can be made without departing from the spiritand scope of the invention, as defined in the accompanying claims.

We claim:

1. A sound-absorbing wall structure for a wall, ceiling, or the like,and having an appearance similar to that of a textured plasteredsurface, said wall structure comprising a substantially non-perviouslayer substantially preventing flow of air therethrough, a plurality offibrous boards, adhesive attaching said boards to said layer inabutting, coplanar relationship, said boards having apparent densitiesbetween approximately seven pounds per cubic foot and twelve pounds percubic foot, a plurality of sheets of fibrous mat of long glass filamentsbonded together by a binder present in an amount of from l0 to 25%, byweight, a second adhesive adhering said sheets llc.

of fibrous mat to said fibrous boards in substantially coplanarrelationship, with joints of said sheets being out of alignment with thejoints of said fibrous boards, and a coating of acoustical paint on theexposed surfaces of said sheets, said coating of paint being on saidsheets in the form of small globules which leave the surfaces of saidsheets porous and provide a textured appearance for said Wall structure.

2. A sound absorbing wall structure for a wall, ceiling, or the like,and having an appearance similar to that of a textured plasteredsurface, said wall structure comprising a substantially non-perviouslayer substantially preventing flow of air therethrough, a plurality offibrous boards, adhesive attaching said boards to said layer inabutting, coplanar relationship, said boards having apparent densitiesbetween approximately seven pounds per cubic foot and twelve pounds percubic foot, a plurality of sheets of fibrous mat of long glass filamentsbonded together by a phenolic binder present in an amount of from 10 to25%, by Weight, a second adhesive adhering said sheets of fibrous mat tosaid fibrous boards in substantially coplanar relationship, with jointsof said sheets being out of alignment with the joints of said fibrousboards, and a coating of water-based paint on the exposed surfaces ofsaid sheets, said coating being on said sheets in the form of globuleswhich leave the surfaces of said sheets porous and provide a texturedappearance for said Wall structure, said coat also hiding the joints ofsaid sheets.

3. A wall structure according to claim 2 wherein sai-d non-perviouslayer comprises heavy kraft paper coated with asphalt.

References Cited in the file of this patent UNITED STATES PATENTS822,602 Gross et al. June 5, 1906 1,894,933 Venzie Jan. 17, y19331,950,420 Stitt Mar. 13, 1934 1,999,856 Austin Apr. 30, 1935 2,205,423Lefebure June 25, 1940 2,450,911 Park et al. Oct. 12, 1948 2,587,884Palmer Mar. 4, 1952 2,692,219 Slayter et al. Oct. 19, 1954 2,703,627DEustachio Mar. 8, 1955 2,850,109 Benjamin Sept. 2, 1958 2,984,312Brisley et al. May 16, 1961 3,025,197 Sheidley Mar. 13, 1962 3,044,919Stoneburner July 17, 1962

1. A SOUND-ABSORBING WALL STRUCTURE FOR A WALL, CEILING, OR THE LIKE,AND HAVING AN APPEARANCE SIMILAR TO THAT OF A TEXTURED PLASTEREDSURFACE, SAID WALL STRUCTURE COMPRISING A SUBSTANTIALLY NON-PERVIOUSLAYER SUBSTANTIALLY PREVENTING FLOW OF AIR THERETHROUGH, A PLURALITY OFFIBROUS BOARDS, ADHESIVE ATTACHING SAID BOARDS TO SAID LAYER INABUTTING, COPLANAR RELATIONSHIP, SAID BOARDS HAVING APPARENT DENSITIESBETWEEN APPROXIMATELY SEVEN POUNDS PER CUBIC FOOT AND TWELVE POUNDS PERCUBIC FOOT, A PLURALITY OF SHEETS OF FIBROUS MAT OF LONG GLASS FILAMENTSBONDED TOGETHER BY A BINDER PRESENT IN AN AMOUNT OF FROM 10 TO 25%, BYWEIGHT, A SECOND ADHESIVE ADHERING SAID SHEETS OF FIBROUS MAT TO SAIDFIBROUS BOARDS IN SUBSTANTIALLY COPLANAR RELATIONSHIP, WITH JOINTS OFSAID SHEETS BEING OUT OF ALIGNMENT WITH THE JOINTS OF SAID FIBROUSBOARDS, AND A COATING OF ACOUSTICAL PAINT ON THE EXPOSED SURFACES OFSAID SHEETS, SAID COATING OF PAINT BEING ON SAID SHEETS IN THE FORM OFSMALL GLOBULES WHICH LEAVE THE SURFACES OF SAID SHEETS POROUS ANDPROVIDE A TEXTURED APPEARANCE FOR SAID WALL STRUCTURE.